[Solved] You wrote this schema:type Query { user(id: ID): User }and resolver:user: (parent, args) => getUserById(args.id)But queries return null always. What is the likely issue? | GraphQL

GraphQL - Basics and Philosophy

You wrote this schema:

type Query { user(id: ID): User }

and resolver:

user: (parent, args) => getUserById(args.id)

But queries return null always. What is the likely issue?

AThe Query type must be named RootQuery

BThe id argument should be non-nullable (ID!) in schema

CThe resolver function is missing a return statement

DThe getUserById function is undefined

Step-by-Step Solution

Solution:

Step 1: Check schema argument type
The id argument is nullable (ID), so queries may omit it causing null results.
Step 2: Fix argument nullability
Making id non-nullable (ID!) ensures queries must provide id, fixing null returns.
Final Answer:
The id argument should be non-nullable (ID!) in schema -> Option B
Quick Check:
Nullable id arg causes null results [OK]

Quick Trick: Use ID! to require id argument in queries [OK]

Common Mistakes:

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